luminous flux


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Related to luminous flux: Luminous efficacy, luminous flux density

Luminous flux

The time rate of flow of light. It is radiant flux in the form of electromagnetic waves which affects the eye or, more strictly, the time rate of flow of radiant energy evaluated according to its capacity to produce visual sensation. The visible spectrum is ordinarily considered to extend from 380 to 760 nanometers in wavelength; therefore, luminous flux is radiant flux in that region of the electromagnetic spectrum. The unit of measure of luminous flux is the lumen. See Photometry

McGraw-Hill Concise Encyclopedia of Physics. © 2002 by The McGraw-Hill Companies, Inc.

Luminous flux

The rate of flow of light, analogous to the rate of flow of a fluid.
Illustrated Dictionary of Architecture Copyright © 2012, 2002, 1998 by The McGraw-Hill Companies, Inc. All rights reserved
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Luminous Flux

 

a photometric quantity. Luminous flux is radiant flux—that is, the power of the optical radiation —evaluated with respect to its capacity to produce visual sensation. More precisely, luminous flux is radiant flux evaluated according to its action on a selective optical detector whose spectral sensitivity is defined as a function of the spectral luminous efficiency V(λ), where λ is the wavelength of the light in a vacuum. The unit of luminous flux is the lumen. The relation between the luminous flux Фv and the radiant flux Фe is given by the equation

Here, Km is the maximum value of the spectral luminous efficacy; Km ≈ 680 lumens per watt at a wavelength of 555 nanometers.

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.

luminous flux

[′lü·mə·nəs ′fləks]
(optics)
The time rate of flow of radiant energy, evaluated according to its capacity to produce visual sensations; measured in lumens.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.

luminous flux

The rate-of-flow of radiant energy emitted by a lamp.
McGraw-Hill Dictionary of Architecture and Construction. Copyright © 2003 by McGraw-Hill Companies, Inc.

luminous flux

The energy field generated by light. See lumen.
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References in periodicals archive ?
Light source Luminous flux At 0.37 W Luminous CRI (Ra) (lm) efficacy (lm/W) WLEDs 53.2 144 82.3 WLEDs with c-SCPhCs 46.7 127 80.1 w-WLEDs 44.3 120 82.5 Light source CCT (K) CIE coordinate (x, y) WLEDs 3974 (0.3806, 0.3744) WLEDs with c-SCPhCs 2960 (0.4428, 0.4114) w-WLEDs 2842 (0.4464, 0.4038)
Then luminous flux for luminaries with directional radiation at planar surface according to (7) can be defined as
For the first selection (2008) the measurement results show that the difference in luminous flux between the LEDs is about 0.5 lm.
where [PHI]--the luminous flux; S--illuminating surface area.
Owing to the smaller diameter of the T5/16 mm fluorescent lamp, the higher luminous flux [2] compared to the T8/26 mm fluorescent lamp and the so-called "cool spot" [5] at one lamp end, it is conceivable to dispense with a closed full-length heat accumulation tube made of shatterproof PC running in parallel to the lamp and instead provide heat accumulation tube sections in the electrode area only.
For historical reasons the fundamental photometric quantity in SI has been luminous intensity which, although it is a property of a light source, can be related to detector quantities by measuring the luminous flux of a source under conditions of known geometry.
Luminous Flux (lm) - 2400 ([+ or -]10%) with 3000K or 2500 ([+ or -]10%) with 4000K or 3500 ([+ or -]10%) with 6000K
The new models produce a light output of up to 2550 lumen (depending on the module), a luminous flux of up to 102 lm/W and a long service life of 40,000 operating hours at a service temperature of 80[degrees]C.
Luminous Flux (lm) - 1850 ([+ or -]10%) with 3000K or 2100 ([+ or -]10%) with 4000K or 2400 ([+ or -]10%) with 6000K
The high-CRI XP-G is available with luminous flux of up to 107 1m at 350 mA in warm white (3000 K), providing efficacy of 102 lm/W.